Hand grenade



H. COBAN HAND GRENADE .Filed May 20, 1938 HAROLD' C'oBA/v INVENTOR gp/W WW Patented Dec. 26, 1939 UNITED STATS PATNT 5 Claims.

My invention relates to hand grenades and has particular reference t grenades adapted to be manually thrown and to explode on impact with an object.

In hand grenades it is necessary to have an attachment whereby the ring pin can be made inoperative until the grenade is'ready to be used. For this purpose, a lever or similar device is used which locks the ring pin in one position but releases it when turned into another position. With such an arrangement, the grenade becomes explosive from the moment when the ring pin is released, i. e., when it is still in the soldiers hands, unless a more or less complicated timing l mechanism is employed.

My invention has for its object therefore to provide means to prevent the grenade from becoming explosive until it has traveled a substantial distance from the point of throwing, rendering thereby the grenade harmless if accidentally dropped or when it hits an obstacle at the beginning of its Eight.

For this purpose, I provide a protective member, preferably in the form of a tube movably supported between the firing pin and fulminate cap or container in the grenade, the tube preventing the ring pin from striking the fulminate. I further provide a rotary inertia operated member so connected with the protective tube as to withdraw the latter from the ring pin when a certain number of revolutions of the rotary member have been completed. A convenient arrangement may be had by providing an outer member preferably in the form of a shell rotatively mounted on the inner shell and adapted to be set in rotation in the act of throwing the grenade, the outer shell then continuing to rotate by inertia on the inner shell.

I Iurther provide a threaded or cam-shaped connection between the outer shell and the protective tube whereby the -tube is withdrawn upon completion of several revolutions of the outer shell.

Another object of my invention is 4to provide a bearing portion for a throwers thumb so as to indicate the correct hold on the grenade in order to impart rotation in the right direction. I also provide means to prevent the relative rotation between the inner shell and the outer member until the grenade is ready to be thrown. For this purpose, I provide a removable'cover for the outer extension of the protective tube, the cover being supported on the outer member and adapted, when closed, to engage a portion of the inner shell or its extension thereby preventing relative displacement of the two shells until the cap is removed.

Still another object of my invention is to provide means to manually'release the `locking mechanism by the fingers of the same hand which is used for throwing the grenade, the

necessity to remove the cover serving automatically as a .direction for properly holding the grenade.

My invention is more fully explained in the accompanying specification and drawing in which- Fig. l is a sectional elevational View showing my hand grenade in the inoperative condition with a protective tube placed over the firing pin.

Fig; 2 is a similar view with the protective tube withdrawn.

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 1. y

Fig. 4 is a fractional elevational view of a modied grenade.

My hand grenade consists of an inner shell I preferably having relatively thick walls of any shape with longitudinal 2 and transverse 3 grooves forming blocks facilitating fragmentation of the grenade when its charge of an explosive material 4 is exploded. The shell has a threaded opening for a tubular member 5 which is tted into the opening from inside the shell, being inserted through an opposite relatively large opening 6 which is also used for charging the shell with the explosive substance, slugs, etc. 'Ihe member 5 has an enlarged portion 1 forming an annular chamber for a container 8 for a 'provide communication between the container and the explosive material in the shell. The container is made of thin sheet metal so that its inner annular wall II can be easily pierced by a ring member I2. The latter-represents a small but relatively heavy piece with pins or points I3 extending in different directions. The enlarged portion 'I is screwed on a tubular extension I4 which is provided with inner threads I5 for a screw plug I6 which also forms a cap for closing the opening 6. Slots I1 are provided in the member I4 for screwing the complete assembly of the tubular member with the portion 'I into the threaded hole in the shell. The plug i6 has a trunnion I8 for a bearing I9 mounted `inside on an outer shell 20 formed of twohalves `joined together by screws 2I or in any other suitable manner. An annular groove 22 is provided at the opposite end of the tubular member forming a second trunnion for the outer shell. A lug 23 extends from the outer shell with a hole 24 ior hanging the grenade on a hook'at the soldiers belt.

The ring member l2 is supported on a spring 25 which may be preferably of a spiral or zig-zag shape and which is iittedat the other end in the screw plug lli. The spring is suillciently stifl` to prevent the ring member from coming in contact with the inner lwall of the fulminate container while the grenade is in flight, but permitting the firing member to strike and pierce the inner wall Il of the container by the force of inertia when the grenade is suddenly 'stopped in its flight, as, for instance, when it strikes an object. The wall Il may be made of a concave form to facilitate its piercing by the pins I3. 'Ihe member I2 can strike the wall il by inertia under action of any force substantially transverse to the axis of the tubular member. In order to cause the member I2 to strike the wall li under action of a force in direction of the axis of the tubular member, guiding pins or members 26 are iitted in the wall of the member I4 opposite curved portions of the spring 25, one guiding pin being located at the right hand loop and the other` pin at the left hand loop of the spring. With this arrangement one pin deects the spring to the side when the force is applied against one end of the tubular member, and to the other side when the force is applied in the opposite direction. The firing member will therefore strike the membrane il under all conditions regardless of which portion of the grenade l strikes an object.

In order to render the grenade safe for handling until it is ready to be used, a protective device is provided in the form of a protective tube 2l slidably iitted in .the tubular member 5 and extending between the points i3 and the wall ii of the container as shown in Fig. 1; The other end of the tube 21 has spiral threads 28. A pin 2Q slides in a slot 30 in the member 5 and prevents rotation of the tube 2l in the member 57. The threaded end of the protective tube extends beyond the end cf the member 5 and is engaged by a lug 3l extending into the threads; the lug is connected with and is a part of the outer shell 2li. A tubular extension 32 is formed on the outer shell around the end of the protective tube and has a lug 33 at one side for the thumb of a soldier indicating the correct way of holding the grenade. A cover 3d is fitted over the extension 32 and is held on a hinge 35, the opposite side of the cover having a tooth 36 resiliently engaging a notch 31 at the lug or lip 5&3 for holding the cover in the closed position. The upper side of the cover is of concave shape so as to lit the surfacel of the outer shell inthe opened position as shown in Fig. 2'. Lugs 32 extend from the cover and t intov corresponding holes in the end of the protective tube in order to prevent therelative rotation between the inner and outer shells when the cover is in the closed position thereby rendering the grenade safe against an accidental turning of the outer shell which may lead to the withdrawal of the protective tube and exposing the fulminate container to the firing member i2. The catch 36 of the cap is made so that it requires a certain effort to release it and to open the cover, thereby minimizing the danger of accidental removal of the cap. It may be noted, however, -that even should the cap be accidentally removed, still it will be necessary for the other shell to make s everal complete revolutions before the nring pin becomes armed.

In order to operate the grenade it is then taken in the right hand, the cover 3l is opened by the thumb and the latter is placed against the lip 33 in order to insure that the shell will have the correct rotation. A left-handed soldier must place his thumb against the eyelet 24. The grenade is then thrown in an' ordinary manner. It should be noted that any ordinary method of throwing will cause the outer shell to rotate while the inner shell resists rotation on account of its considerable inertia. The outer shell will continue to rotate on the trunnions on the inner shell by inertia,

causing the lug 3| to slide in the threads 28, since this lug has been inserted into the threads in assembly. The tube 21 being prevented from rotation by the pin 29, it will move outward under pressure of the lug 3l sliding in the threads,v until the movement is stopped by the pin 29 reaching the other end of the slot 30. The threads may be so proportioned that the explosion of the firing member is obtained after the grenade has passed a certain distance of its flight. It follows therefore that the grenade will remain harmless during the first portion of'its flight and cannot possibly explode if accidentally dropped in the act of throwing or if it hits a nearby object. At the same time, the lug 3l prevents the screw from sliding back when the grenade hits an object.

A modiied construction is shown in Fig. 4. The protective tube 39 has internal threads 40 for a screw di having a square end 42 fastened to the outer shell by a cap nut 43. A thin breakable pin it holds the outer shell against the tubular member 5 or against the inner shell. The pin prevents accidental displacements of the outer shell on the inner shell but -is readily broken when the grenade is thrown, the rotational torque imparted in this case being suillcient to break the pin thereby releasing the outer shell for rotation. The screw il will rotate with the outer shell drawing the tube 39 away from the firing member. The outer shell will readily burst open when the inner shell explodes, the small screws 2| offering but little resistance to the shearing force. The outer shell can also be made so that it will break into fragments, for which purpose it can bemade withY a plurality of slots 45 with a thin lining AS underneath made of metal foil or similar material for keeping the dirt out. The outer shell may be provided with serrations or ridges, or othervwise roughened in order to increase the frictional engagement with the operators hand. This arrangement will also facilitate the operation of throwing the grenade by a catapult or similar mechanical device, rendering. 'the same more effective.

it is understood that my hand grenade may be further modified without departing from the spirit of my invention as set forth in the appended claims.

l claim as my invention:

1. A hand grenade comprising a shell, a tubular member supported at its ends in the Walls of the shell, the shell being adapted to contain explosives, an annular container for a fulminate in the tubular member, a plug in the tubular member, a star-shaped firing member, and a spring yieldably supporting at one end the firing member centrally of the annular container the other end of the spring being supported on the plug, the inner wall of the container being made of a thin material adapted to be pierced by the firing pin, the spring being adapted to be deected sidewise by the force of inertia acting on. the g in any direction thereby causing the pin to pierce the wall of the fulminate container.

2. A hand grenade comprising a shell, a tubular member supported at its ends in the walls of the shell, the shell being adapted to contain explosives, an annular container for a fulminate in the tubular member, a plug in the tubular member, a star-shaped ring member, a curved spring yieldably supporting the firing member at one end centrally of the annular container the other end of the spring being supported on the plug, the inner wall of the container being made of a thin material adapted to be pierced by the ring pin, means cooperating with the spring for tion to the inner shell.

defiecting the spring sidewise so as to cause the firing pin to strike the inner wall of the container by the force of inertia acting in any direction, a protective sleeve slidably tted between the fulminate and the iiring pin, and inertia operated means to withdraw the sleeve when the grenade is given a rotary motion.

3. A hand grenade-comprising an inner shell having oppositely located apertures, a tubular` member tted into one of the apertures and extending substantially to the middle of the shell, an annular container for a fulminate tted concentrically in the inner end of the tubular member, a plug tted into the other aperture and engaging the inner end of the tubular member, a spring on the plug extending into the tubular member, a ring pin on the end of the spring, the spring beingadapted to be deflected sidewise by the force of inertia acting on the pin in any direction, the pin being adapted to pierce the inner wall of the container when deiiected by the force of inertia, the'tubular member having apertures around the container, the inner shell being adapted to be lled with explosives, a sleeve slidably tted in the tubular member and interposed between the ring pin and the inner wall of the container, an outer shell rotatatively tted on the outer extensions of the tubular member and the plug, and a threaded connection between the outer shell and the sleeve for withdrawing the sleeve, thereby arming the grenade when the outer shell is rotated in rela- 4. A hand grenade comprising an inner shell having oppositely located apertures,I a tubular member fitted into one of the apertures and extending substantially to the middle of the shell,

an annular container for a fulminate tted concentrically in the inner end of the tubular member, a plug fitted into the other aperture and engaging the inner end of the tubular member,

a spring in the plug extending into the tubularmember, a tiring .pin on the other end of the spring, the spring being adapted to be deflected sidewise' by the force of inertia acting on the pin in any direction, the pin being adapted to pierce the inner wall of the container when deilected by the force of inertia, the tubular member having apertures around the container, 'the inner shell being adapted to be filled with explosives, a sleeve slidably fitted in the tubular member and interposed between the firing pin and the inner wall of the container, an outer shell rotatively tted on the outer extensions of the tubular member and the plug, a threaded connection between y(the outer shell and the sleeve for withdrawing the sleeve thereby arming the grenade when the outer shell is rotated in relation to the inner shell, a cap removably iitted on the outer shell adapted to coverl the end of the tubular member, and means on the cap for preventing relative rotation between the inner and outer shells .when the cap is closed.

5. A hand grenade comprising an inner shell having oppositely located apertures, one of the apertures being substantially larger than the other, a tubular member tted into the smaller aperture and extendingtoward the larger aperture, the shell being adapted to tbefilled'with explosives through the larger aperture, a plug p closing the larger aperture and engaging the end of the tubular member, the tubular member hav-A ing an inner annular recess and being provided with apertures in the wall surrounding the recess, an annular thin-walled container for a fulminate fitted in the recess, a ilrlng pin yieldably supported on the plug in the tubular member inside the container, the inner wall of the container being adapted to be pierced by the pin when the latter is deflected by the force of inertia, coaxial extensions on the plug and on the 'tubular member, an outer shell rotatively supported on the extensions, a protective sleeve enclosing the iiring pin and slidably tted in the tubular member, and means to withdraw the l protective sleeve by the relative rotation between the inner and outer shells.

HAROLD COBAN. 

